Mankind has long felt compelled to measure the passage of time within a day. Early, pre-mechanical devices such as the sundial, marked candles and the hour glass addresses the desire, albeit in rather primitive ways. With the dawning of the mechanical age, gears and pendulums enabled the development of timepieces that we would recognize today. Early clocks were rather large and expensive, but in this century, mass-production and the mainspring brought the wristwatch within the grasp of the common man. In the last decade or so, electronic technology saw the introduction of the digital, numeric-readout watch. This seemed at once a marvel of technology, but people soon realized the ergonomic advantage of the traditional analog readout.
Various patents disclose digital timepieces. U.S. Pat. No. 3,841,082 discloses a binary clock wherein four lights indicate the hour according to the binary numbering system, four lights indicate the five-minute interval within an hour according to the binary numbering system, and four lights indicate the minute interval within a particular five-minute interval according to the decimal numbering system. This display requires special training to read since it does not correlate well to a traditional timepiece with hands.
Japanese Pat. No. 52-21864 discloses what we might call the "traditional" digital watch. A four-digit display indicates the hours (two digits) and the minutes (two digits).
U.S. Pat. No. 4,254,489 discloses a timepiece simulating a clock using dial hands. The hands, in this case, are sixty liquid crystal elements emanating radially from the center of the dial. While benefiting in readability as a more direct analog of mechanical hands, the liquid crystal elements are tightly packed, and spacing becomes a problem, especially towards the center of the dial. Also, the hands are not very visible in attenuated light.
U.S. Pat. No. 4,488,818 discloses a timepiece with a hybrid display of mechanical hands and a digital, numeric readout. The purpose of having two time displays within a single timepiece is to be able to view the time in two time zones simultaneously. The resulting "busy" display is unattractive to many people.
U.S. Pat. No. 3,854,279 discloses apparatus for indicating time including a plurality of electric lamps having different colors corresponding to different times of the day. Its outward appearance is more like a lamp than a clock, and the relationship of particular lamps being illuminated to time is rather obscure.
German Patent Publication No. 2,725,029 discloses a timepiece with an analog display using LEDs or liquid crystal cells arranged in a point or line raster. The display elements are coupled to an control circuit energizing time in sequence to provide an analog representation of the clock hands. The display comprises concentric rings divided into 60 segments, the different rings being used for the hours, minutes and seconds hands respectively.
German Patent Publication No. 2,751,551 discloses a watch with an analog LED or LCD display. As in the above mentioned U.S. Pat. No. 4,254,489, the display consists of elongated segments emanating radially from the center of the dial.
U.S. Pat. Nos. 4,075,826, 4,120,148, 4,448,544, 4,207,734 and 4,074,515 all disclose electronic circuitry controlling the operation of a digital timepiece.
A problem with the aforementioned timepieces is that they are not as easily readable as a traditional mechanical timepiece having radial hands circulating about a dial. There are several reasons for this. First is the high degree of visual contrast obtained from, for instance, black hands and a white dial. Even in those cases of electronic watches having LCD elements representative of hands, the elements are of necessity quite thin, and are lacking in the requisite contrast, due in part to the fact that the elements are in the plane of the dial, and the dial is very "busy" with quiescent elements. This is even more pertinent in the context of a watch. Small size is anathema to many of the aforementioned timepieces.
Another problem is that while the aforementioned electronic watches are technically quite sophisticated, we have become acclimated, such as through early exposure to mechanical wall clocks in school and at home, to the somewhat more primitive, imprecise readout of a mechanical timepiece with hands. While, for instance, a digital numeric-readout watch can indicate exactly what minute and second it is, such accuracy is typically not desired, and it is burdensome to have to read the digits. In contrast to this, one can tell at a glance the time from a mechanical timepiece; for instance, about a quarter after three, almost ten thirty, etc. When more precision is called for, we can tell the time to the minute, and even to the second if a second hand is provided.
The third problem, which relates back to the visual presentation, is that in mechanical timepieces the hands, hour, minute and second, are very distinctive, one from another. Thus we can focus, almost in a reflexive manner, upon the relevant hand(s). For instance, one may already know that he is within the hour of seven, and is only concerned with the minute hand to know when seven thirty arrives.
In summary, a common problem in the previous electronic readout timepieces is that too much cognition is required. SUMMARY OF THE INVENTION
Therefore, it is an object of this invention to provide a timepiece having a more readable display.
According to the invention, the dial of a timepiece is provided with a first circular array of twelve blue LEDs indicating hours, a second next-outermost array of sixty red LEDs indicating minutes, and a third next-outermost array of sixty green LEDs indicating seconds.
According to an aspect of the invention, every fifth red "minute" LED is distinct from the intermediate "minute" LEDs in that it is either spaced farther apart from the adjacent LEDs or is larger than the adjacent LEDs, or both.
According to a feature of the invention, a switch is provided in the timing circuit of the timepiece to select between a "normal" mode of operation wherein the sixty "minute" LEDs are energized in sequence, at the passage of each minute and a "teaching" mode of operation wherein only every fifth "minute" LED is energized, in sequence, at the passage of each five minute interval.
The timepiece may be a watch, a clock or the like.
Other objects features and advantages of the invention will become evident in light of the following description thereof.